var url;
chrome.webRequest.onBeforeRequest.addListener(details => {
        var extract = (details.url).split('\.');
        var extract2 = extract[extract.length-1].substring(0,3);
		//兼容全民K歌
        var extractKG = extract[extract.length-1].substring(0,4);
        var extractKG2 = extractKG.substring(3,4);
        //全民k歌结束
        if(extract2 == "aac" || extract2 == "mp3" || extract2 == "m4a" && extractKG2 != "%"){
            url = details.url;
            return;
        }
}, {urls: ["<all_urls>"]});
